summaryrefslogtreecommitdiffstats
path: root/lib
diff options
context:
space:
mode:
Diffstat (limited to 'lib')
-rw-r--r--lib/bitops.c21
-rw-r--r--lib/bitops.h2
-rw-r--r--lib/ipv4.h10
-rw-r--r--lib/ipv6.h20
4 files changed, 53 insertions, 0 deletions
diff --git a/lib/bitops.c b/lib/bitops.c
index 6ca0505..88cef78 100644
--- a/lib/bitops.c
+++ b/lib/bitops.c
@@ -45,3 +45,24 @@ u32_masklen(u32 x)
if (x & 0xaaaaaaaa) l++;
return l;
}
+
+/**
+ * u32_log2 - compute a binary logarithm.
+ * @v: number
+ *
+ * This function computes a integral part of binary logarithm of given
+ * integer @v and returns it. The computed value is also an index of the
+ * first non-zero bit position.
+ */
+
+u32
+u32_log2(u32 v)
+{
+ u32 r, shift;
+ r = (v > 0xFFFF) << 4; v >>= r;
+ shift = (v > 0xFF ) << 3; v >>= shift; r |= shift;
+ shift = (v > 0xF ) << 2; v >>= shift; r |= shift;
+ shift = (v > 0x3 ) << 1; v >>= shift; r |= shift;
+ r |= (v >> 1);
+ return r;
+}
diff --git a/lib/bitops.h b/lib/bitops.h
index 1b6dc68..bebd830 100644
--- a/lib/bitops.h
+++ b/lib/bitops.h
@@ -17,3 +17,5 @@
u32 u32_mkmask(unsigned n);
int u32_masklen(u32 x);
+
+u32 u32_log2(u32 v);
diff --git a/lib/ipv4.h b/lib/ipv4.h
index 4c4fab9..b64d9b2 100644
--- a/lib/ipv4.h
+++ b/lib/ipv4.h
@@ -35,6 +35,7 @@ typedef u32 ip_addr;
#endif
+#define MAX_PREFIX_LENGTH 32
#define BITS_PER_IP_ADDRESS 32
#define STD_ADDRESS_P_LENGTH 15
#define SIZE_OF_IP_HEADER 24
@@ -58,6 +59,9 @@ typedef u32 ip_addr;
#define ipa_from_u32(x) _MI(x)
#define ipa_to_u32(x) _I(x)
#define ipa_compare(x,y) ipv4_compare(_I(x),_I(y))
+/* ipa_pxlen() requires that x != y */
+#define ipa_pxlen(x, y) ipv4_pxlen(_I(x), _I(y))
+#define ipa_getbit(x, y) (_I(x) & (0x80000000 >> (y)))
#define ip_skip_header(x, y) ipv4_skip_header(x, y)
@@ -78,6 +82,12 @@ static inline int ipv4_compare(u32 x, u32 y)
return (x > y) - (x < y);
}
+static inline u32 ipv4_pxlen(u32 a, u32 b)
+{
+ return 31 - u32_log2(a ^ b);
+}
+
+
#define IP_PREC_INTERNET_CONTROL 0xc0
#endif
diff --git a/lib/ipv6.h b/lib/ipv6.h
index 191c1c7..9193c4f 100644
--- a/lib/ipv6.h
+++ b/lib/ipv6.h
@@ -12,6 +12,7 @@
#include <sys/types.h>
#include <netinet/in.h>
#include "lib/string.h"
+#include "lib/bitops.h"
typedef struct ipv6_addr {
u32 addr[4];
@@ -23,6 +24,7 @@ typedef struct ipv6_addr {
#define _I2(a) ((a).addr[2])
#define _I3(a) ((a).addr[3])
+#define MAX_PREFIX_LENGTH 128
#define BITS_PER_IP_ADDRESS 128
#define STD_ADDRESS_P_LENGTH 39
#define SIZE_OF_IP_HEADER 40
@@ -57,6 +59,9 @@ typedef struct ipv6_addr {
/* ipa_from_u32 and ipa_to_u32 replaced by ipa_build */
#define ipa_build(a,b,c,d) _MI(a,b,c,d)
#define ipa_compare(x,y) ipv6_compare(x,y)
+/* ipa_pxlen() requires that x != y */
+#define ipa_pxlen(x, y) ipv6_pxlen(x, y)
+#define ipa_getbit(x, y) ipv6_getbit(x, y)
#define ipa_absolutize(x,y) ipv6_absolutize(x,y)
ip_addr ipv6_mkmask(unsigned);
@@ -81,6 +86,21 @@ static inline unsigned ipv6_hash(ip_addr *a)
return (x ^ (x >> 16) ^ (x >> 8)) & 0xffff;
}
+static inline u32 ipv6_getbit(ip_addr a, u32 y)
+{
+ return a.addr[y / 32] & (0x80000000 >> (y % 32));
+}
+
+static inline u32 ipv6_pxlen(ip_addr a, ip_addr b)
+{
+ int i = 0;
+ i+= (a.addr[i] == b.addr[i]);
+ i+= (a.addr[i] == b.addr[i]);
+ i+= (a.addr[i] == b.addr[i]);
+ i+= (a.addr[i] == b.addr[i]);
+ return 32 * i + 31 - u32_log2(a.addr[i] ^ b.addr[i]);
+}
+
/*
* RFC 1883 defines packet precendece, but RFC 2460 replaces it
* by generic Traffic Class ID with no defined semantics. Better